Well lads here's my view on the subject, I've done a 25yr. unintentional experiment on predation, I moved here in 1986 with 40 race birds, once broken they have been on open loft, Brechfa Forest starts a few hundred yards from me it's 6,500 hectares, about 2.4 acres to a hectare, hawk heaven, The open loft mob are still around 50 and I collect eggs all the time. 2010 I bought in new stock, new loft and the youngsters flown as normal race birds, losses on the old mob are low but losses on the birds flown as normal are horrendous in comparison, I certainly would never shut my birds up for several months, they would be so unfit, lambs to the slaughter comes to mind